Supplementary Material for: Selective COX-2 inhibitor is beneficial in suppressing chronic postoperative pain in esophageal cancer patients and may prolong patient survival

Introduction: Chronic postsurgical pain (CPSP) is a common complication after surgical procedures. Radical resection of esophageal cancer is a complex procedure, one of the most extensive and traumatic surgical procedures in oncological surgery, and the incidence of postoperative chronic pain is high, seriously affecting patients' postoperative recovery. Therefore, this study aims to investigate the incidence of CPSP in patients with esophageal cancer and to analyse the risk factors associated with its occurrence, in order to provide certain prevention and treatment ideas for clinical prevention and reduction of CPSP. Methods: Patients with radical esophageal cancer resection were selected as the study subjects, and the clinical data regarding to patients' preoperative comorbidities, ASA grading, surgical method, use of selective COX-2 inhibitor, postoperative analgesic pump use and patients' postoperative tumor recurrence time were collected. The differences in clinical data between the CPSP group and no CPSP group were compared to analyse the risk factors for the occurrence of CPSP. Results: A total of 262 patients were included, 57 (21.76%) developed CPSP, and there were statistical differences between the two groups in terms of selective COX-2 inhibitor and postoperative analgesic pump use rates and surgical modality (p<0.05), and logistic regression analysis showed that age and length of surgery increased the risk of CPSP, perioperative selective COX-2 inhibitor use decreased the the risk of CPSP occurrence (p<0.05), the extent of tumor infiltration and regional lymph node metastasis were risk factors for shortening tumor-free survival (TFS), and age and use of selective COX-2 inhibitor were influential factors for prolonging TFS (p<0.05). Conclusion: Patients with esophageal cancer have a high incidence of postoperative chronic pain, with youth and length of surgery being risk factors for CPSP, and perioperative pain management with selective COX-2 inhibitor can reduce the incidence of CPSP and is associated with prolonged tumor-free survival.

引言：慢性术后痛（Chronic postsurgical pain, CPSP）是外科手术后常见的并发症。食管癌根治术是肿瘤外科中操作最广泛、创伤性最强的复杂手术之一，术后慢性疼痛发生率较高，严重影响患者术后康复。因此本研究旨在调查食管癌患者术后慢性痛的发生率，并分析其发生的相关危险因素，以期为临床预防及降低慢性术后痛发生率提供防治思路。
方法：本研究选取食管癌根治术患者作为研究对象，收集患者术前合并症、美国麻醉医师协会（ASA）分级、手术方式、选择性环氧合酶-2（COX-2）抑制剂使用情况、术后镇痛泵使用情况及术后肿瘤复发时间等临床资料。比较慢性术后痛组与非慢性术后痛组患者的临床资料差异，以分析慢性术后痛发生的危险因素。
结果：本研究共纳入262例患者，其中57例（21.76%）发生慢性术后痛；两组患者在选择性COX-2抑制剂使用率、术后镇痛泵使用率及手术方式方面差异均具有统计学意义（p<0.05）。Logistic回归分析显示，年龄与手术时长会增加慢性术后痛发生风险，围术期使用选择性COX-2抑制剂可降低其发生风险（p<0.05）；肿瘤浸润程度与区域淋巴结转移是缩短无瘤生存期（TFS）的危险因素，而年龄与选择性COX-2抑制剂使用是延长无瘤生存期的影响因素（p<0.05）。
结论：食管癌患者术后慢性痛发生率较高，年龄与手术时长为慢性术后痛的危险因素，围术期采用选择性COX-2抑制剂进行疼痛管理可降低慢性术后痛发生率，且与延长无瘤生存期相关。